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Dissecting Basilar Artery Aneurysm in Marfan Syndrome:
Case Report
Barry S. Rose 1 and Diane L. Pretorius
We describe a 35-year-old man with Marfan syndrome who
died as a result of rupture of a basilar artery dissecting
aneurysm. To the best of our knowledge, this association has
not been presented before.
Case Report
A 35-year-old man with Marfan syndrome presented to the emergency room with a severe occipital headache of several hours duration . The headache differed from his usual migraine headaches both
in quality and in unresponsiveness to Cafergot.
The patient's medical history included repair of an ascending aortic
aneurysm and replacement of a bicuspid aortic valve 2112 years
previously. The patient was receiving chronic anticoagulant therapy.
A noncontrast enhanced CT of the brain obtained on admission
was unremarkable. Concurrent lumbar puncture yielded CSF with
628 RBCjmm 3 , 2 WBCjmm 3 , and subsequently negative Gram stain
and cultures . Although a traumatic lumbar puncture was a consideration , a cerebral arteriogram was performed because of clinical
suspicion of a vascular lesion . The arteriogram showed a fusiform
aneurysm of the basilar artery extending into the left superior cerebellar artery and the left posterior cerebral artery (Figs. 1A and 1B).
The patient became briefly unresponsive the day after admission.
A repeat lumbar puncture revealed grossly bloody CSF with
2,730 ,000 RBCjmm 3 and 10,700 WBCjmm 3 .
Anticoagulant therapy was discontinued . The subsequent unenhanced CT scan of the brain demonstrated subarachnoid blood in
the basal cisterns . The patient died on the 14th day of hospitalization .
Postmortem examination of the brain confirmed a basilar artery
and contiguous vessel aneurysm. Subarachnoid hemorrhage was
present around the brainstem and rostral spinal cord . Histologic
sections showed an intimal tear in the basilar artery with dissection
and transmural rupture . Most of the dissection plane was within the
media of the basilar artery (Fig . 1C). Sections of the basilar (Fig . 1 D)
and systemic arteries showed multiple foci of cystic medial necrosis,
consistent with Marfan syndrome .
Discussion
Marfan syndrome is an autosomal dominant inherited disorder of connective tissue, probably due to an error in protein
metabolism, possibly in collagen or elastin . In its classic form ,
the syndrome is associated with abnormalities of the eye
(ectopia lentis), aorta, and skeleton. The expressivity of the
classic Marfan gene varies widely. The rate of occurrence of
de novo mutations is estimated at 15% of all cases [1].
The cardiovascular abnormalities in Marfan syndrome include dilatation of the aortic ring , dilatation of the ascending
aorta, and dissection of the aorta. Coarctation of the aorta
has also been described. Extraaortic manifestations include
dilatation andjor dissecting aneurysms of the pulmonary arteries and cardiac valvular and septal defects [1] .
Other extraaortic vascular involvement is rare. Austin and
Schaefer [2] reported a case of innominate artery and bilateral
carotid artery dissection without aortic dissection in a patient
with Marfan syndrome. Tortuosity and elongation of the basilar artery have been previously noted in Marfan syndrome
but are rare [3, 4] . To the best of our knowledge basilar artery
dissection and rupture have not been reported before in this
syndrome.
Dissecting aneurysms of the intracranial arteries are uncommon . Intracranial dissecting aneurysms have a high morbidity and mortality rate [5] in contrast to the usual benign
course of cervical carotid artery dissections [6]. Dissections
involving the intracranial portion of the carotid artery and
middle cerebral artery typically cause infarction, but posterior
intracranial artery dissections have less predictable sequelae.
Vertebrobasilar dissections have two major clinical presentations , depending on the arterial plane of dissection: ischemia
and subarachnoid hemorrhage [7] . If the dissection plane is
between the intima and media, vessel occlusion and infarction
occur. In our case, the dissection extended transmurally , with
the greatest length of dissection within the vessel media.
Preexistent changes of collagen necrosis were present in this
layer.
Intracranial arterial dissections occur most often in young
adults (late 20s to early 40s) [5]. with no predisposing condition identified in most cases [7] . Isolated cases related to
fibromuscular dysplasia, cystic medial necrosis , arteriosclerosis , syphilis , migraine, homocystinuria, and trauma have
been reported [5] .
Received June 13, 1990 ; revision requested August 15, 1990; revision received November 8, 1990 ; accepted November 18, 1990.
' Both authors: Department of Radiology, Aultman Hospital, 2600 Sixth St., S.W., Canton, OH 44710. Address reprint requests to B.S. Rose.
AJNR 12:503-504, May 1June 1991 0195-6108/9 1/ 1203-0503 © American Society of Neuroradiology
504
ROSE AND PRETORIUS
AJNR:12, MayfJune 1991
Fig. 1.-A, Anteroposterior view from left vertebral arteriogram shows dilatation of basilar,
left superior cerebellar, and left posterior cerebral arteries. Note intervening narrowing in left
superior cerebellar artery (arrow), which suggests dissection.
8 , Lateral view from left vertebral arteriogram
shows same findings.
C, Histologic section of basilar artery shows
intramural thrombus from dissection (asterisk).
The lumen (L), internal elastic membrane
(straight arrow), and media (M) are marked. Note
that the thrombus splits the media (curved arrow) and extends to the adventitial layer (arrowhead). (H and E stain)
D, Histologic section of basilar artery shows
small vacuoles and blue-staining mucosubstance within media layer (M), indicating degeneration. L lumen, arrow internal elastic membrane, asterisk = dissection thrombus. (Aician
blue stain)
=
Angiographically, no single feature has been identified in all
cases of intracranial arterial dissection. A narrowed , tapered ,
or irregular segment {"string sign ") or total occlusion distal to
an irregular narrowed segment is often observed. Fusiform
dilatation proximal to the dissection andjor poststenotic dilatation ("string and pearl sign") also have been described [8].
A double lumen is pathognomonic but is rarely seen. In our
patient, the fusiform basilar artery aneurysm with lumenal
narrowing of the proximal left superior cerebellar artery and
dilatation of the more distal left superior cerebellar artery
corresponded with the dissection that was present at autopsy .
In summary, a 35-year-old man with Marfan syndrome and
previous aortic repair died following rupture of a basilar artery
dissecting aneurysm. The presence of basilar artery dissection represents a rare association in this syndrome.
=
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